Conversion of hydrocarbon oils



Oct. 29, 1935;

FURNACE [6 c. H. ANGELL 2,018,699

CONVERSION OF HYDROCARBON OILS Filed April 17, 1931 FRACTIONATOR INVENTQR CHARLES H. ANGELL Patented Oct. 29, 1935 UNITED STATES CONVERSION or HYDROCARBON OILS Charles H. Angeli, Chicago, 111., assignor to Universal Oil Products Company, Chicago, 111., a corporation of South Dakota Application April 17, 1931, Serial No. 530,740

4 Claims.

This invention relates to the treatment of hydrocarbon oils and particularly refers to the conversion of relatively heavy oils into substantial yields of lower boiling and more desirable products.

Primarily the present invention comprises subjecting a hydrocarbon oil to conversion conditions in a cracking system and subjecting the insufliciently converted intermediate products of conversion to further conversion in the same cracking system under independently controlled conversion conditions.

A more specific embodiment of the invention may comprise subjecting hydrocarbon oil to conversion conditions in a. heating element, introducing the heated products into a reaction zone, withdrawing both liquid and vaporous products from said reaction zone and introducing them into a zone of reduced pressure where vapors may separate from the residual material, subjecting the vapors to fractionation, subjecting the desirable light components of the vapors to condensation and cooling and collecting the resulting products, subjecting the relatively heavy insufficiently converted components 0! the vapors which may be condensed in the fractionating zone to further conversion in a separate heating element, introducing the heated products into a separate reaction zone, withdrawing both liquid and vaporous products from said separate reaction zone and introducing them into the aforementioned zone of reduced pressure.

The attached diagrammatic drawing illustrates one form of apparatus embodying the principles of the present invention. The following description of the drawing embraces also a description of the'process of the invention as it may be practiced in the apparatus illustrated.

Raw oil charging stock may be supplied through line I and valve 2 to pump 3, from which it may be fed through line 4 and valves 5 and 6 into heating element '1. A portion or all of the raw oil may, if desired, be preheated prior to its introduction into heating element 1. This may be accomplished for example by diverting all or any desired portion of the raw oil from line 4 through line 8 and valve 9, into preheating coil 10, which may be located within the fractionator II and wherein the oil during passage therethrough may be heated by indirect contact with the relatively hot vapors in the fractionator. The preheated oil may thence pass through line 12 and valve l3 back into line 4, flowing thence toheating element 1. If desired, a portion of the raw oil either pre heated or unpreheated may pass directly into fractionator II. This may be accomplished for example by diverting a portion or all of the oil fed through line 8 into fractionator through line l4 and valve l5.

Heating element 1 may be located within any 6 suitable form of furnace l6 and the oil passing therethrough may be heated to the desired conversion temperature under any desired pressure conditions and may be discharged through line 1 l and valve I8 into reaction chamber l9. Heating 10 element 1 and chamber I9 are preferably maintained under a substantial superatmospheric pressure and the pressure employed in chamber 19 may be substantially the same or lower than that employed in the heating element. Both 1 liquid and vaporous products may be withdrawn from chamber 19 through line 20 and valve 21 and may be discharged through line 22 and valve 23' into vaporizing chamber 24, which is preferably maintained under a substantially reduced 2 pressure relative to that employed in chamber 19 and wherein vapors may be separated from the residual products of conversion. The residual liquid may be withdrawn from chamber 24 through line 25 and valve 26 to cooling and stor- 25 age or to any desired further treatment, or if desired conditions may be .so regulated in chamber 2 1 that substantially all of the volatile components of the residuum are vaporized in this zone, leaving only a relatively dry carbonaceous residual product, in which case the carbon or coke may collect within chamber 24 to be removed after the operation of the process is discontinued. If desired, a plurality of chambers, similar to chamber 24 but not here illustrated, may be 35 employed for the accumulationof the, carbonaceous product and may be operated either alternately or simultaneously to permit prolonged operation of the process. Vapors may be withdrawn from chamber 24 through line 21 and valve 28 to fractionation in fractionator H. The relatively light desirable components of the vapors may be withdrawn from the fractionator through line 29 and valve 30 and may be subjected to condensation and cooling in condenser 3|, products from 45 which may pass through line 32 and valve 33 to be collected in receiver 34. Uncondensable gas may be released from the receiver through line 35 and valve 36. Distillate may be withdrawn through line 31 and valve 38. A portion of the distillate may, if desired, be withdrawn from receiver 34 through line 39 and valve 40 to herecirculated by means of pump 4| through! line .42 and valve 43 to the upper portion of, fraetionator H to assist fractionation of the vapors in this zone.

The relatively heavy insufiiciently converted components of the vapors subjected to fractionation may be condensed in fractionator II and may pass, alone or together with that portion, ii any, of the raw oil charging stock introduced directly into the fractionator as already prescribed, through line 44 and valve 45 to pump 46. Pump 45 may supply the reflux condensate from fractionator H, alone or together with a portion of the raw oil charging stock, asthe case may be, through line 41 and valve 48Ito heating element Heating element 49 may be located within a suitable form of furnace 50 and the oil supplied to this heating element is subjected preferably to more severe conversion conditions than those employed in heating element 1. The heated oil may be discharged through line 5i and valve 52 into'reaction chamber 53. Preferably heating element 49 and chamber 53 are both maintained under a substantial superatmospheric pressure, and the pressure employed in chamber 53 may be either substantially the same or lower than that employed in the heating element. Both liquid and vaporous products may be withdrawn from chamber 53 through line 54 and valve 55 and may pass through line 22, where they may commingle with the products withdrawn from chamber i9, passing therewith through valve 23 to chamber 24.

Pressures employed within the system may range from substantially atmospheric to superatmospheric pressures as high as 2000 pounds per square inch or more. Conversion temperatures may range from 800 to 1200 F. more or less. The heating element and reaction chamber in which all or the major portion of the raw oil charging stock is processed preferably employs temperatures of the order of 800 to 950 F. and superatmospheric pressures of the order of 100 to 500 pounds per square inch. The heating element and reaction chamber in which reflux condensate from the system is subjected to further conversion, may employ liquid-vapor-phase conversion conditions with temperatures of the order of 875 to 950 F. and pressures ranging from 100-to 500 pounds per square inch or thereabouts or vaporphase conversion conditions may be employed in this portion of the system utilizing temperatures preferably of the order of 950 to 1200 F. and relatively low pressures ranging from substantially atmospheric to 100 pounds per square inch or thereabouts. Pressure conditions employed in the vaporizing, fractionating, condensing and collecting portions of the system may range preferably from substantially atmospheric to 100 pounds per square inch or thereabouts.

As a specific example of operating conditions which may be employed in the practice of the invention and results obtainable therefrom, a 22-24 A. P. I. gravity fuel is the raw oil charging stock for the system, substantially all of which is subjected to a conversion temperature of approximately 875 F. under superatmospheric pressure of about 250 pounds per square inch in the heating element. Substantially the same pressure is maintained in the reaction chamber where quick separation of vapors and residual oil is effected and wherein conversion of the vaporous products may continue. The reflux condensate from the fractionator of the system is subjected in a separate heating element to conversion temperature of approximately 950 F.

under superatmospheric pressure of about 350 pounds per square inch. The reaction chamber operated in conjunction with this heating element is also maintained under a pressure of about 350 pounds per square inch and, as in the other 5 reaction chamber, continued conversion of the vapors and quick separation of vapors and residual liquid may be effected. Streams of both vapor and residual liquid from both reaction chambers are introduced into the vaporizing 10 chamber, which is maintained under a reduced pressure of about 35 pounds per square inch, which pressure is substantially equalized in the fractionating, condensing and collecting portions of the system. This operation may yield ap- 16 proximately 66% motor fuel having an antiknock value approximately equivalent to a blend of 55% benzol and 45% straight run Pennsylvania gasoline. In addition, about 25% of good quality residual oil suitable for sale as fuel maybe pro- 20 duced. No appreciable amount of coke or carbonaceous material is produced, the only other product of the process being a rich uncondensable gas.

In another operation utilizing the same charg- 26 ing stock'the raw oil is subjected to conversion temperature of approximately 890 F. with a pressure of approximately 300 pounds per square inch in the heating element and reaction chamber, while the reflux condensate is subjected to a temperature of approximately 1000 F. with a pressure of approximately pounds per square inch in the separate heating element and reaction chamber. A plurality of low pressure coking zones are employed alternately and the operation 88 may yield approximately 72% of motor fuel having a benzol equivalent of approximately 60%, the only other products being about 100 pounds of coke or carbonaceous material per barrel of raw oil processed and a rich uncondensable gas.

I claim as my invention:

1. In a process of hydrocarbon oil conversion wherein hydrocarbon oil is subjected to cracking conditions of temperature and pressure in a primary heating zone, the heated hydrocarbon 5 mass passed to a reaction zone, the vaporous and liquid products of reaction removed from said reaction zone and introduced intoa separating zone wherein vapors separate from non-vaporous material, the vapors subjected to fractionation in a 50 fractionating zone to separate the sufficiently converted components as vapor from the insuiiiciently converted components as reflux condensate, the improvement which comprises, subjecting reflux condensate from said fractionating zone to con- 55 version conditions of temperature and pressure in a secondary heating zone, p assing the heated bydrocarbons from said latter zone to a secondary reaction zone, and removing the vaporous and liquid products of reaction from said reaction zone on and; introducing the same in company with the products of reaction from the primary reaction zone to said separating zone.

2. In a processof hydrocarbon oil conversion where hydrocarbonoil is subjected to cracking 55 conditions ,of temperature and pressure in a primary heating zone, the heated hydrocarbon mass passed to a reaction zone, the vaporous and liquid products of reaction removed from said reaction zone and introduced into a zone of reduced pres- 19 sure wherein vapors separate from non-vaporous material, the vapors subjected to fractionation in a fractionating zone to separate the suificiently converted components as vapor from the insufliciently converted components as reflux con- 1 densate, the improvement which comprises, subjecting reflux condensate from said fractionating zone to conversion conditions of temperature and pressure in a secondary heating zone, passing the heated hydrocarbons from said latter zone to a secondary reaction zone, and removing the vaporous and liquid products of reaction from said reaction zone and introducing the same in company with the products of reaction from the primary reaction zone to said zone of reduced pressure.

3. In a process of hydrocarbon oil conversion wherein hydrocarbon oil is subjected to cracking conditions of temperature and pressure in a primary heating zone, the heated hydrocarbon mass passed to a reaction zone, the vaporous and liquid products of reaction removed from said reaction zone and introduced into a separating zone wherein vapors separate from non-vaporous material, the vapors subjected to fractionation in a fractionating zone to separate the sufficiently converted components as vapor from the insufficiently converted components as reflux condensate, the improvement which comprises, subjecting reflux condensate from said fractionating zone to independently controlled conversion conditions of temperature and pressure in a secondary heating zone, passing the heated hydrocarbons from said latter zone to a secondary reaction zone, and removing the vaporous and liquid products of reaction from said reaction zone and introducing the same in company with the products of reaction from the primary reaction zone to said separating zone.

4. In a process of hydrocarbon oil conversion wherein hydrocarbon oil is subjected to cracking conditions of temperature and pressure in a primary heating zone, the heated hydrocarbon mass passed to a reaction zone, the vaporous and liquid products of reaction removed from said reaction zone and introduced into a separating zone wherein vapors separate from non-vaporous material, the vapors subjected to fractionation in a fractionating zone to separate the sufficiently converted components as vapor from the insufliciently converted components as reflux condensate, and a portion of the charging stock for the system is commingled with the vapors undergoing fractionation within said fractionating zone, the improvement which comprises subjecting the reflux condensate together with the heavier portions of the charging stock from the fractionating zone to conversion conditions of temperature and pressure in a secondary heating zone, passing the heated hydrocarbons from said latter zone to a secondary reaction zone, removing the vaporous and liquid products of reaction from said reaction zone and introducing the same in company with the products of reaction from the primary reaction zone to said separating zone.

CHARLES H. ANGELL. 

